Protein degradation and its regulation are being studied. We are specifically studying: 1. Binding of enzymes to subcellular membranes as a possible prerequisite for uptake into lysosomes or inactivation. Included are studies on the effects of ligands on binding and the possible involvement of phosphorylated sugars. 2. Purification and characterization of an isocitrate-dehydrogenase-inactivating factor. 3. Testing the effects of ligands on inactivation or proteolytic attack of various enzymes including serine dehydratase and acetyl CoA carboxylase. 4. Testing the effects of dietary changes on lysosomal properties and on lysosomal enzymes in mouse liver.